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Biomedical subjects

R D Soloway

Publications and source records attributed to R D Soloway.

At least 37 records · Page 2Linked to original sources
PubMed1986

Hepatolithiasis in East Asia. Retrospective study.

Hepatolithiasis is a major disease in Asia but differences in operative incidence between countries have not been examined. A retrospective study was conducted in Taiwan, Hong Kong, and Singapore, and the results were compared with those in Japan with the aim of defining factors involved in the etiology of the condition. In order to ensure uniformity of the data collected, the same form was used throughout the study and was completed by the same personnel after reviewing the patient's record and radiographs in each case. The years 1976-1980 were chosen for the study, since the newer methods of diagnosis such as ultrasound, endoscopic retrograde cholangiography, and percutaneous transhepatic cholangiography became available during that period. The most significant finding was the difference in the relative prevalence of hepatolithiasis as a proportion of all gallstone cases in Taiwan, Hong Kong, and Singapore, where the majority of the population consisted of patients of Chinese descent. The highest prevalence, 53.5%, was found in Taiwan, while in Hong Kong it was 3.1% and in Singapore 1.7%. Environmental rather than ethnic factors are implicated in the cause of hepatolithiasis.

Adult↗
PubMed1986

Chemical and morphologic characteristics of cholesterol gallstones that failed to dissolve on chenodiol. The National Cooperative Gallstone Study.

During the National Cooperative Gallstone Study, chenodiol (chenodeoxycholate), 750 or 375 mg/day, resulted in complete gallstone dissolution in only 13.5% and 5.2% of patients, respectively. The purpose of this study was to analyze the composition and morphology of gallstones from patients who underwent cholecystectomy during the National Cooperative Gallstone Study to determine if calcium salts on the gallstone surface could have been responsible for failure of dissolution. Total gallstone calcium content was not different between the treated and placebo groups; however, surface calcium levels were different, being greater than 1.0% in 47.6% of stones from chenodiol-treated patients (n = 63) but in only 16.7% of those from placebo-treated patients (n = 18), p less than 0.02. Pigmented outer rims were found in 52.4% of the stones from the chenodiol-treated group compared with only 16.7% of stones from the placebo group, p less than 0.01. The rim calcium content of 36 stones with pigmented outer rims was 3.7% +/- 1.0%, whereas that of 45 stones with nonpigmented outer rims was only 1.0% +/- 0.3%, p less than 0.01. We conclude that the presence of rings of increased concentrations of calcium salts on the gallstone surface may impair dissolution by chenodiol.

Bilirubin↗
PubMed1986

Azathioprine and hepatic venocclusive disease in renal transplant patients.

We report 3 cases of hepatic venocclusive disease occurring in renal transplant patients receiving azathioprine and combine our experience with 4 other previously reported cases. The data suggest a clinical syndrome characterized by (a) delayed clinical onset, (b) striking male predominance, (c) presentation with jaundice followed by evidence of portal hypertension, and (d) poor prognosis. One of our patients, who is still alive 40 mo after the first onset of symptoms of liver disease, showed striking clinical improvement with discontinuation of azathioprine and subsequent deterioration on reinstitution. We suggest that azathioprine may be closely linked with the development of venocclusive disease in renal transplant patients and that the frequency of this disorder may be more common than previously reported. To attempt to prevent a fatal outcome, this group of patients should be closely monitored for the earliest signs of hepatic venocclusive disease through periodic serum bilirubin and alkaline phosphatase determinations. Patients with abnormal tests should undergo liver biopsy. If hepatic venocclusive disease is found, prompt withdrawal of azathioprine is indicated.

Adult↗
PubMed1985

Cancer of the gallbladder in Bolivia: suggestions concerning etiology.

In order to investigate the very high incidence of gallbladder cancer in Bolivia, a series of patients with gallbladder cancer and/or cholelithiasis from a hospital in La Paz was compared to a series of patients with cholelithiasis from Philadelphia. Each group demonstrated a similar female predilection. Bolivian patients with gallbladder cancer were older than patients with cholelithiasis who, in turn, were older than the general population (p less than 0.001). Racial differences demonstrated previously were confirmed. Bolivian gallstones were uniformly cholesterol in type, in contrast to the US series, in which 27% of patients had black pigment stones. Bile specimens obtained from Bolivian patients with cholelithiasis had a lower concentration of bile salts, phospholipids, and cholesterol than bile specimens from US cholelithiasis patients (p less than 0.01, less than 0.001, and less than 0.001, respectively). These biochemical differences may help to explain the differing incidence of cholelithiasis and gallbladder cancer in the US and Bolivia.

Bile↗
PubMed1985

Cyclic deposition of calcium salts during growth of cholesterol gallstones.

Some cholesterol gallstones contain darkly pigmented centers or peripheral concentric pigmented bands. We examined the cross-sectional surface of three cholesterol gallstones which contained both central and peripheral pigmented areas with electron-probe microanalysis (EPM) and energy dispersive x-ray microanalysis (EDXA) to determine the elemental composition of the pigmented regions. Linear EPM across the cross-sectional surface of the stones demonstrated that most of the pigmented regions of all three stones had high Ca and P signals; the non-pigmented intervening areas had markedly lower or no detectable Ca and P signals. In two of the three stones, high O signals coincided with the high Ca and P signals suggesting that both calcium bilirubinate and calcium phosphate were present in these pigmented areas. EDXA of the central and peripheral pigmented areas of each stone confirmed the presence of a high Ca signal. Our results demonstrate that in some cholesterol gallstones there is cyclic deposition of calcium bilirubinate and other calcium salts.

Bile Acids and Salts↗
PubMed1979

Ultrasonic properties of gallstones. Effect of stone size and composition.

In vivo and in vitro ultrasonic characteristics of gallstones were compared with stone size and composition with the aim of understanding the basis for these features. In vivo and in vitro ultrasonic features of the same stone were identical. Acoustic shadowing was not due to stone type, radiodensity, or calcium content. However, all stones larger than 4 mm in diameter produced a distinct sonic shadow. Gallbladder sludge produced internal echoes without a sonic shadow. These echoes shifted slowly when the patient was reexamined in a different position. Four of seven cholesterol stones containing more than 88% cholesterol floated and produced a sonic shadow without internal echoes or with an area of internal echoes within the gallbladder at a distance from the posterior wall. This last feature may identify patients that are good candidates for a trial of gallstone dissolution with chenodeoxycholic acid.

Bilirubin↗
PubMed1978

Pigment gallstone composition in cirrhotic and noncirrhotic subjects.

The composition of pigment gallstones from patients with and without cirrhosis was compared. Carbonate-containing pigment stones were distinguished from noncarbonate stones by infrared spectroscopy. Calcium was the major cation of each stone group. The major anion in noncarbonate pigment stones was bilirubinate or phosphate, but was carbonate in carbonate stones. The composition of pigment stones from cirrhotic and noncirrhotic patients was similar except that significantly less carbonate was present in carbonate stones, and less pigment (bilirubinate) was present in noncarbonate stones from noncirrhotics. These data suggest that irrespective of the presence of cirrhosis, the formation of noncarbonate pigment stones involves the selective precipitation of calcium bilirubinate and phosphate, whereas carbonate stone formation involves the selective precipitation of calcium carbonate.

Age Factors↗
PubMed1978

Biliary lipid excretion in patients with pigment gallstones. A comparison with cholesterol gallstone patients.

Pigment gallstone patients are believed to have normal biliary lipid excretion. In order to measure this and to better understand cholesterol gallstone formation, the kinetics of biliary lipid excretion were studied in three patients who had been cholecystectomized for pigment gallstones and the results compared to those previously obtained in patients cholecystectomized for cholesterol gallstone. Pigment-stone patients had hyperbolic relationships between cholesterol and phospholipid outputs and bile salt output which were similar to those seen in cholesterol-stone patients. However, pigment-stone patients excreted more cholesterol and phospholipid at high bile salt output but approached those levels more gradually than cholesterol-stone patients. As a result, pigment-stone patients produced bile undersaturated with cholesterol at a lower bile salt output than cholesterol-stone patients, and thus they would be less likely to produce supersaturated bile during low bile salt output such as that occurring during an overnight fast. The data suggest that cholesterol-stone patients, in addition to excreting more cholesterol and less bile salts than normals, have a defect in the rate of lipid output in response to decreasing bile salt output.

Adult↗
PubMed1978

Factors affecting delivery of bile to the duodenum in man.

Studies utilizing balloon-occludable T or duodenal tubes in subjects with and without gallbladders were undertaken to identify the contribution of the gallbladder, the sphincter of Oddi, and bile salts to the delivery of bile to the duodenum. Patients with and without a functional sphincter of Oddi and with and without a gallbladder were compared. The presence of a functional sphincter of Oddi in duodenal tube patients reduced bile salt output by more than 67% from that observed in T-tube patients. When cholecystectomized and normal patients were compared using the duodenal tube, peak bile salt output was significantly increased in normal subjects, reflecting gallbladder contraction, but total bile salt output was not significantly increased suggesting that the gallbladder has a minor role in bile delivery. Exogenous infusion of cholecystokinin produced much more stable bile secretion than did endogenous release of cholecystokinin by intraduodenal infusion of essential amino acids. This rhythmic release of bile after endogenous cholecystokinin release was related to the concentration of bile salts in the intestinal lumen. Thus, delivery of bile to the duodenum is wave-like and is predominantly controlled by the sphincter of Oddi.

Adult↗
PubMed1977

Pigment gallstones.

Pigment gallstones are defined as any dark brown-to-black stone, consisting of calcium salts of bilirubin, phosphate, carbonate and other anions, and can be separated into carbonate- and noncarbonate-containing groups. Pigment stones predominate in the rural Orient, in cirrhosis, and in elderly United States patients undergoing cholecystectomy. Clinical associations include bile duct obstruction, stasis, and possibly hemolysis. Of pigment stones, 50% are radioopaque and account for two-thirds of all opaque stones. The concentrations of bile salts, phospholipids,, cholesterol, and total bilirubin in bile are similar to normal levels, but the concentration of unconjugated bilirubin is increased in the bile of some patients. Increased unconjugated bilirubin in bile may be caused by increased hydrolysis of excreted conjugated bilirubin. Unconjugated bilirubin is solubilized by bile salts, but the interaction is primarily nonmicellar. Ionized calcium and pH are important determinants of solubility. Sulfated glycoproteins, excreted in increased amounts in patients with cholelithiasis, may be the site of pigment stone precipitation because these compounds bind calcium salts tightly. E coli is frequently cultured from pigment stones in Japan but not in the United States; thus, bacterial beta-glucuronidase may be important in stone formation in Japan but probably not in the West. Stasis leads to increased calcium secretion and to increases in the concentration of sparingly soluble compounds that may then precipitate. Incomplete emptying of the gallbladder may result in the same concentration process. Unsaturated fats and chronic vagal stimulation cause pigment stone formation in animals. At present, surgery is the only treatment for pigment lithiasis.

Adolescent↗
PubMed1977

Pigment versus cholesterol cholelithiasis: identification and quantification by infrared spectroscopy.

We previously reported that 27% of 92 cholecystectomized patients had pigment stones (Am J Dig Dis 19:585-590, 1974). Using standard biochemical methods, we found that cholesterol accounted for an average of 77% of the dry weight of cholesterol stones, but that unconjugated bilirubin represented a mean of only 7% of pigment stones. This quantitation of pigment stones was limited because approximately 66% of their weight was insoluble. To characterize pigment and cholesterol stone composition further, we used infrared spectroscopy--a technique requiring neither crystallinity nor solubilization--to quantitate pigment, carbonate, and cholesterol in gallstones. Other organic and inorganic components of stones were measured by standard methods. By infrared spectroscopy, two types of pigment stones were identified: carbonate-containing and noncarbonate pigment stones. Carbonate pigment stones contained significantly more calcium, carbonate, and phosphate, but less pigment than noncarbonate stones. Compared to our initial report, the total measured components of all pigment stones were increased 6-fold from 10 to 63%. Cholesterol was the major component of cholesterol stones by chemical assay or infrared spectroscopy. Among five cholesterol stones with limited solubility, 80% of the insoluble residue was identified as cholesterol by infrared spectroscopy. This study extends our knowledge of pigment stone and cholesterol stone composition by the use of quantitative infrared spectroscopy in conjunction with standard biochemical methods; furthermore, it confirms that pigment and cholesterol stones differ in composition and form by different mechanisms.

Carbonates↗
PubMed1977

Factors affecting bilirubin excretion in patients with cholesterol or pigment gallstones.

To identify factors affecting bilirubin excretion, the effects of bile flow and bile salt excretion on bilirubin output into bile have been examined in normobilirubinemic, cholecystectomized patients with balloon-occludable, reinfusion T-tubes, 8 patients with cholesterol (CS) and 2 with pigment (PS) gallstones. Another patient with pigment gallstones, sickle cell disease (SS), and stable jaundice was studied to examine the mechanism by which an increased bilirubin load was excreted. Total bilirubin was almost entirely conjugated and excretion was related linearly to bile salt excretion PS and CS subjects; one-third of bilirubin excretion was bile salt independent and two-thirds was bile salt associated. In the SS patient 90% of the bilirubin excretion was independent of bile salt output. In PS and CS patients, bilirubin output was linearly related to bile flow, but the SS patient showed significant bilirubin excretion at low flow rates. CS and PS patients had similar patterns of bilirubin excretion, but the increased bilirubin load in the SS patient was excreted independently of bile salts. In the SS patient, unconjugated bilirubin output was hyperbolically related to bile salts output and represented a maximum of 3% of the total bilirubin output. The bile salt-independent excretion of conjugated bilirubin suggests that micelles were not required for transport into bile; whereas the hyperbolic relationship for unconjugated bilirubin and bile salt output, similar to that of the micellar lipids. cholesterol, and phospholipids, suggests interaction with micelles.

Adult↗
PubMed1976

Kinetic analysis of biliary lipid excretion in man and dog.

To understand better the mechanisms involved in biliary lipid excretion and to evaluate their role in cholesterol gallstone formation, the rates of biliary excretion of bile salts, cholesterol, and phospholipids were measured in two species, man and dog. Seven cholecystectomized patients with balloon-occludable reinfusion T-tubes were studied during intact and interrupted enterohepatic circulation and four cholecystectomized dogs were studied during interrupted enterohepatic circulation. In man and dog both cholesterol and phospholipid outputs were hyperbolically related to bile salt output by the equation y = x/(a + bx). The output curves intersected the origin and showed an initial rapid rise, followed by a slower increase to a maximum, suggesting a rate-limited mechanism. The shape of the curves permitted calculation of the theoretical maximal outputs and the rates of rise to those outputs. Comparison of these values showed that in both man and dog phospholipid output was greater than cholesterol output and that cholesterol and phospholipid were excreted at different rates. These studies (a) indicate that cholesterol, phospholipids, and bile salts are not excreted in a fixed relationship and (b) demonstrate the usefulness of the derived theoretical maximal lipid output, and the rate of rise of lipid excretion to a maximum, in evaluating the kinetics of biliary lipid excretion.

Adult↗
PubMed1975

Prospective, randomized study of diagnosis and outcome in acute upper-gastrointestinal bleeding: endoscopy versus conventional radiography.

Sixty patients with mild to moderate upper-gastrointestinal bleeding were admitted to a prospective, controlled study of diagnosis and management, and were randomized to endoscopy or upper-gastrointestinal (UGI) barium series as the initial study. Definitive localization of the source of bleeding was made initially in 69% of the endoscopy group and 21% of the UGI group (P less than 0.0005). Of 54 patients undergoing both studies, endoscopy was definitive in 67% and UGI series in 22%. Thus, endoscopy also made more diagnoses when used as the second study (P less than .01). The use of endoscopy as the initial procedure led to significantly more rapid diagnosis than with UGI series. However, there were no significant differences between the two groups in clinical outcome. Endoscopy is the initial diagnostic procedure of choice in patients with mild to moderate upper-gastrointestinal bleeding because it enables detection of superficial bleeding lesions and has significantly increased the speed of diagnosis.

Acute Disease↗